1. Field of the Invention
The present invention relates to a camera device, a mobile terminal and a frame rate controlling method. Specifically, the present invention relates to a camera device, mobile terminal and frame rate controlling method that brings an image into focus by auto focusing (AF).
2. Description of the Related Art
Conventionally, mobile terminals equipped with camera device which bring an image into focus by autofocusing have been widely known. One example of apparatuses of such a kind is disclosed in Japanese Patent Application Laying-Open No. 2008-145760 [G02B 7/28, G03B 13/36, G02B 7/36, H04N 5/232] laid-open on Dec. 11, 2006. An automatic focusing system of the related art has an image pickup device for imaging and an image pickup device for AF (autofocusing) onto each of which the same image is irradiated. Thus, in a focus control, a set of focus lenses is adjusted on the basis of video signals acquired from the image pickup device for AF. Furthermore, in the focusing system, an electronic shutter speed and a frame rate are increased in speed to the extent that shortage of the light amount occurs, which improves follow-up characteristics in focusing.
However, in the automatic focusing system of the related art, the two image pickup devices are operated for focus control, thus, an area of a circuit to which the automatic focusing system is employed is made large, making the power consumption high. Thus, the automatic focusing system of the related art is never used in mobile terminals, such as mobile phone apparatuses for which their small size and low power consumption are challenges.